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Nogueira JJ. New challenges for photopharmacology and computational modeling. Trends Biochem Sci 2022; 47:822-823. [PMID: 35597714 DOI: 10.1016/j.tibs.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/04/2022] [Accepted: 05/05/2022] [Indexed: 11/25/2022]
Abstract
Mous et al. recently reported the molecular mechanism of chloride transport through a light-activated pumping rhodopsin, a key process involved in a range of cellular functions. Their results open exciting new challenges for photopharmacology and computational modeling that should be addressed in the coming years.
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Affiliation(s)
- Juan J Nogueira
- Chemistry Department, Universidad Autónoma de Madrid, 28049, Madrid, Spain; IADCHEM, Institute for Advanced Research in Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
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Finol-Urdaneta RK, McArthur JR, Korkosh VS, Huang S, McMaster D, Glavica R, Tikhonov DB, Zhorov BS, French RJ. Extremely Potent Block of Bacterial Voltage-Gated Sodium Channels by µ-Conotoxin PIIIA. Mar Drugs 2019; 17:md17090510. [PMID: 31470595 PMCID: PMC6780087 DOI: 10.3390/md17090510] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/13/2019] [Accepted: 08/24/2019] [Indexed: 12/15/2022] Open
Abstract
µ-Conotoxin PIIIA, in the sub-picomolar, range inhibits the archetypal bacterial sodium channel NaChBac (NavBh) in a voltage- and use-dependent manner. Peptide µ-conotoxins were first recognized as potent components of the venoms of fish-hunting cone snails that selectively inhibit voltage-gated skeletal muscle sodium channels, thus preventing muscle contraction. Intriguingly, computer simulations predicted that PIIIA binds to prokaryotic channel NavAb with much higher affinity than to fish (and other vertebrates) skeletal muscle sodium channel (Nav 1.4). Here, using whole-cell voltage clamp, we demonstrate that PIIIA inhibits NavBac mediated currents even more potently than predicted. From concentration-response data, with [PIIIA] varying more than 6 orders of magnitude (10−12 to 10−5 M), we estimated an IC50 = ~5 pM, maximal block of 0.95 and a Hill coefficient of 0.81 for the inhibition of peak currents. Inhibition was stronger at depolarized holding potentials and was modulated by the frequency and duration of the stimulation pulses. An important feature of the PIIIA action was acceleration of macroscopic inactivation. Docking of PIIIA in a NaChBac (NavBh) model revealed two interconvertible binding modes. In one mode, PIIIA sterically and electrostatically blocks the permeation pathway. In a second mode, apparent stabilization of the inactivated state was achieved by PIIIA binding between P2 helices and trans-membrane S5s from adjacent channel subunits, partially occluding the outer pore. Together, our experimental and computational results suggest that, besides blocking the channel-mediated currents by directly occluding the conducting pathway, PIIIA may also change the relative populations of conducting (activated) and non-conducting (inactivated) states.
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Affiliation(s)
- Rocio K Finol-Urdaneta
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
- Department of Biochemistry, Brandeis University, Waltham, MA 0254-9110, USA.
| | - Jeffrey R McArthur
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Vyacheslav S Korkosh
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint Petersburg 194223, Russia
| | - Sun Huang
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Denis McMaster
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Robert Glavica
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Denis B Tikhonov
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint Petersburg 194223, Russia
| | - Boris S Zhorov
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint Petersburg 194223, Russia
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 4K1, Canada
| | - Robert J French
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
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Wu M, Sun L, Zhou Q, Peng Y, Liu Z, Zhao S. Molecular Mechanism of Acetate Transport through the Acetate Channel SatP. J Chem Inf Model 2019; 59:2374-2382. [DOI: 10.1021/acs.jcim.8b00975] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Meng Wu
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
- University of Chinese
Academy of Sciences, No. 19A, Yuquan Road, Beijing 100049, China
| | - Liping Sun
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Qingtong Zhou
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Yao Peng
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Zhijie Liu
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Suwen Zhao
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
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Sakipov S, Sobolevsky AI, Kurnikova MG. Ion Permeation Mechanism in Epithelial Calcium Channel TRVP6. Sci Rep 2018; 8:5715. [PMID: 29632318 PMCID: PMC5890290 DOI: 10.1038/s41598-018-23972-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 03/20/2018] [Indexed: 12/14/2022] Open
Abstract
Calcium is the most abundant metal in the human body that plays vital roles as a cellular electrolyte as well as the smallest and most frequently used signaling molecule. Calcium uptake in epithelial tissues is mediated by tetrameric calcium-selective transient receptor potential (TRP) channels TRPV6 that are implicated in a variety of human diseases, including numerous forms of cancer. We used TRPV6 crystal structures as templates for molecular dynamics simulations to identify ion binding sites and to study the permeation mechanism of calcium and other ions through TRPV6 channels. We found that at low Ca2+ concentrations, a single calcium ion binds at the selectivity filter narrow constriction formed by aspartates D541 and allows Na+ permeation. In the presence of ions, no water binds to or crosses the pore constriction. At high Ca2+ concentrations, calcium permeates the pore according to the knock-off mechanism that includes formation of a short-lived transition state with three calcium ions bound near D541. For Ba2+, the transition state lives longer and the knock-off permeation occurs slower. Gd3+ binds at D541 tightly, blocks the channel and prevents Na+ from permeating the pore. Our results provide structural foundations for understanding permeation and block in tetrameric calcium-selective ion channels.
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Affiliation(s)
- Serzhan Sakipov
- Chemistry Department, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA, 15213, USA
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th St., New York, NY, 10032, USA
| | - Maria G Kurnikova
- Chemistry Department, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA, 15213, USA.
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